The urinary incontinence care products available on the market today range from enlarged versions of the familiar disposable infant diapers to cumbersome pants arrangements, with many variations between these extremes. Some of the products are effective against leakage and odor emission, but are difficult to dispose of and/or cumbersome and/or heavy and/or uncomfortable to wear for long periods whether wet or dry. Others, which are less cumbersome, heavy or uncomfortable, appear to be less effective against leakage and odor emission. Thus a need exists for urinary incontinence care products or systems which are smooth and close fitting rather than bulky, are readily disposable, exert relatively little localized pressure on the skin and yet effectively stay in place, and are light in weight and effective against leakage and emission of odors.
The present invention arose in part from attempts to produce satisfactory urinary incontinence care pads from absorbent materials which are capable of being formed into layers and which are highly absorbent, i.e. capable of absorbing at least about 5, more particularly at least about 15, and most preferably at least about 35 times their own weight of water or urine. One example of such layers of highly absorbent material is a commercially available "sandwich" comprising a central film of polymeric material, such as for instance lightly cross-linked, partially saponified polyacrylate or polyacrylamide that is water absorbent (including water-swellable), having a cellulosic fiber layer on each of its major surfaces.
Heretofore, in the attempt to produce absorptive pads for the care of patients subject to urinary incontinence, it has been assumed that at least some patients would require a pad having both a large ultimate absorption capacity and a relatively high rate of absorption. For example, in severe applications, where sudden and major evacuations of liquid are likely, it is believed that a urinary incontinence care pad should be capable of absorbing, without substantial run off or loss of liquid, at least about 150, or 200, or 250 cc. or more of urine at evacuation rates of at least 5 or 10 or more cc. per second, and that the pad should have the foregoing absorption rate coupled with an ultimate capacity of at least about 200, or 250, or 300 or more cc.
Heretofore, attempts to obtain the desired capacity and rate by forming pads from commonly available high-absorbency sheet materials have proved disappointing. In those instances where high capacities were obtained, absorption rates proved inadequate. Thus, it has been indicated that when the above-mentioned high absorbency sheet materials are present in the pad in sufficient amounts to constitute about 50% or more of the total absorption capacity of the pad, inadequate absorption rates result.
Heretofore, various attempts have been made to improve the absorption properties of the above-mentioned highly absorptive materials. It is reported that the manufacturer of one form of such material considered the forming of holes in the material. However, it is understood that the attempt was abandoned due to fear of loss of absorbent material as a consequence of punching pieces of absorbent material out of the sheet, with consequent loss of ultimate absorption capacity. It is also understood that there was some experimentation with forming small pinpricks or slits in such layers of highly absorptive materials, but these proved to be of little if any benefit. It has also been reported that in order to obtain satisfactory results one must employ short slits of controlled length which open and then close after a period of absorption.
From the foregoing, it may be seen that a need remains for rate-enhanced, liquid absorbent pads having high absorption capacity, and if such pads are to be used in the care of urinary incontinence, there is a need for them to be compact and readily disposable, such as by flushing in a common toilet. The principal objectives of the present invention are to fulfill the above needs.